The argument/discussion surrounding vehicular cycling vs. a separated infrastructure has been going on for about 40 years in the US. If you're reading this, you probably already knew that. Here is what I think, initially.
I started riding as a 'roadie'. I rode purely for recreation on a road bike in good weather on local roads. I became comfortable with traffic. I perfectly fit into the demographic of a vehicular cyclist (male age 20-40).
I am still very comfortable riding on the road with vehicles and still commute on the road regularly (I have an option to commute via an unpaved MUP also). However, I have "seen the light" of bicycles for transportation and I believe they are a cost-effective and practical solution to many problems plaguing the US today. To get there, however, requires getting more people on bikes. Here's the rub.
It doesn't matter how much time you spend telling/teaching someone that they are
1) a legitimate user of the roadway and should behave as such and
2) very safe on the road and very unlikely to be in an accident with a car.
People will make their decision based on whether or not they FEEL safe, not whether or not the ARE safe. So we can keep arguing amongst ourselves about the proper treatment of bicyclists on the roadways/bikeways. Or we can work to create infrastructure to get more people riding bikes.
It just comes down to this: Are you more interested in being respected as a vehicular cyclist, asking drivers to share the road, and always being in a very small majority, or are you interested in seeing more people on bikes? Both are fine, but don't expect non-bicyclists to accept your VC argument. They never will.